1. Field of the Invention
The present invention relates to an ink roller device for use with a printing head of a label printing and applying machine or a printing and tagging machine, both preferably of the portable type.
2. Description of the Prior Art
In portable label printing and applying machines (hereafter referred to as a "hand labeler") and in printing and tagging machines, a spongy ink impregnated roller is rolled over the type characters of printing wheels or printing bands to supply them with ink prior to imprinting labels or tags. When the ink supply in the ink roller is consumed, there are a number of techniques of ink resupply.
In one method, the syringe-shaped injecting mouth of an ink bottle is pushed against the outer periphery of an ink roller, and the ink roller is progressively supplied and impregnated with the ink as its periphery turns past the ink bottle. Since the ink penetrates into the spongy roller from its outer periphery, this method of ink resupply consumes much time with resulant inefficiency. Moreover, it is difficult to effect uniform ink impregnation of the deep and outer peripheral portions of an ink roller having considerable thickness. This may cause irregular ink application to the type characers, leading to irregular and unclear imprinting of the labels and tags. Moreover, excessive ink will drop to stain the inside of the machine or the printed labels and tags. Further, the fingers or clothing of the operator as well as a commodity being labeled or tagged are often stained with ink. As a result, ink resupply has been disliked by the labeler operators.
A second method of ink resupply is comprised of replacing a used ink roller with a new ink impregnated roller. Usually, the ink roller itself is pinched directly by the fingers of the operator, and its shaft is pulled in the axial or transverse direction for the subsequent replacement. As a result, the fingers and clothes of the operator are stained, and the assembly and disassembly of the ink roller holder, the ink roller and the ink roller shaft invite trouble and have disadvantages.
In a third method of ink resupply, the ink roller and its holder are assembled into a unitary structure which is replaced as a whole by a new assembly. This involves so high a cost that it has never been placed into practical use.